How do you improve Power Factor?

There are various improvements that can be made within an electrical system which will assist in the improvement of the facilities Power factor.

The replacement of existing motors with more energy efficient ones; ensuring motors are properly sized for their application and duty cycle; the use of high power factor lighting ballasts; and the Installation of Power Capacitors to name a few.

The installation of Power Capacitors is by far perhaps the most straight forward and most cost efficient method of improving a facilities Power Factor.

Ideally, to derive the maximum benefit, properly sized static capacitor banks should be located as close as possible to the offending loads.

Most times however, this may not be the most cost effective method of correction due to the sheer number of static capacitor banks that are required in a large electrical environment.

A more economical method is the installation of a centrally located automatic switching power factor correction bank (APFC). This capacitor bank is controlled by a microprocessor-based relay, which continually monitors the reactive power requirements. The relay then connects or disconnects capacitors to supply capacitance as needed.

Often times, we can take advantage of the use of both types of correction. Static capacitor banks can be placed at strategic locations through out facility while implementing an APFC to handle the remaining requirements for capacitance. Generally, APFCs are placed centrally at the main electrical panel.

Regardless of which strategy is implemented careful planning should be undertaken to ensure maximum benefit is derived from the correction. Other factors that need to be taken into consideration during this planning phase is Harmonics on the electrical system as well as know future expansions to the facility.